Search PubMed⌕ Search

Biomedical subjects

H Meshkinpour

Publications and source records attributed to H Meshkinpour.

At least 19 recordsLinked to original sources
PubMed1992

Sphincter of Oddi dysfunction and unexplained abdominal pain: clinical and manometric study.

Unexplained, biliary-type abdominal pain is often attributed to an abnormal pressure profile of the sphincter of Oddi. In spite of this assumption, the true prevalence of this type of motor dysfunction among cholecystectomized patients with unexplained abdominal pain is not known. We studied 64 postcholecystectomy patients who were thought to have sphincter of Oddi dysfunction. Radiologically, other than a dilated common bile duct in some, they had no anatomic derangement of their pancreatobiliary tract to explain their symptoms. They were categorized into three groups on the basis of four objective findings suggesting abnormal biliary emptying mechanism. Basal sphincter of Oddi pressure, frequency of phasic contractions, and proportion of retrograde contractions were determined in all patients. Twenty-six (41%) of the patients demonstrated at least one motor abnormality, 16 (25%) had two, and 10 (16%) had all three abnormal parameters. The pressure profile of the sphincter was normal in 38 or 59% of the patients. Seventy-three percent (73%) of the patients in group I, who had three or four of the objective findings for sphincter of Oddi dysfunction, demonstrated at least one motor abnormality. Sixty percent of this group demonstrated an increased basal sphincter of Oddi pressure. On the other hand, only 19% of the patients in group III, who had none of the objective findings, revealed a motor abnormality. Increased basal sphincter of Oddi pressure was noted in 7% of this group. We conclude that, sphincter of Oddi dysfunction, as diagnosed manometrically, explains the recurrent biliary type abdominal pain in a minority of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Pain↗
PubMed1992

Achalasia evolving from segmental aperistalsis.

A 17-year-old woman was evaluated for dysphagia. Radiologic study revealed a rigid segment 10 cm long in the midesophagus, which was found to be aperistaltic on manometric evaluation. The rest of the esophagus and the lower esophageal sphincter were manometrically normal. Four years later the patient was seen for evaluation of severe dysphagia and symptoms of esophageal overflow. Characteristic radiologic and manometric findings of classic achalasia were noted. The case is discussed as an atypical form of achalasia evolving from a segmental esophageal aperistalsis.

Adolescent↗
PubMed1992

The role of the flow rate of the pneumohydraulic system on post-sphincter of Oddi manometry pancreatitis.

Manometry of sphincter of Oddi (SO) carries a risk of acute pancreatitis by a mechanism not yet clearly understood. This study attempted to evaluate the role of the flow rate of the perfusion system in the development of acute pancreatitis. During the past 60 months, we have performed 81 manometry studies of SO in 79 patients, 61 women and 18 men, who were referred for recurrent attacks of abdominal pain suggestive of SO dysfunction. All procedures were done by the same operator, utilizing the same instrumentation and similar premedication. In the first 54 studies, the pneumohydraulic system had a flow rate of 0.55 ml/min and a tank pressure of 15 lb/in2 while in the last 27 studies a flow rate of 0.27 ml/min and a pressure of 7.5 lb/in2 were employed. Acute pancreatitis was diagnosed after 16 (19.7%) procedures. Fourteen (26%) of them occurred after high-flow-rate perfusion. In contrast, only 2 (7%) of the 27 patients who had the procedure done at the flow rate developed this complication (p less than 0.05). There was no correlation between the occurrence of pancreatitis, clinical suspicion of SO dysfunction, and the underlying manometric profile of the sphincter. We conclude that the incidence of procedure-related pancreatitis after manometry of SO is higher than following diagnostic endoscopic retrograde cholangiopancreatography and that the flow rate in the perfusion system is a precipitating factor in the development of this complication.

Acute Disease↗
PubMed1992

Manometric and radiologic correlations in achalasia.

Achalasia is an esophageal motor disorder distinguished by clinical, radiologic, and manometric features. To evaluate the correlation among these features, we studied 109 achalasia patients. The four most common clinical complaints, the four most commonly encountered radiologic findings, and two manometric parameters were analyzed with a correlation matrix test and a multiple regression analysis. Significant correlation existed among symptoms of dysphagia, regurgitation, and weight loss. In contrast, chest pain inversely correlated with these symptoms. Dysphagia and weight loss significantly correlated with a bird-beak deformity but not with esophageal dilatation or a sigmoid esophagus. Moreover, no significant relationship between lower esophageal sphincter pressure and esophageal dilatation or sphincter pressure and sigmoid esophagus was found. However, in those patients with a resting lower esophageal sphincter pressure greater than 45 mm Hg, a reasonable correlation among clinical, radiologic, and manometric parameters did exist. In conclusion, although in a subset of patients with markedly increased lower esophageal sphincter pressure, a good correlation between clinical, radiologic, and manometric findings exists, such a correlation cannot be established in all of the achalasia patients; esophageal dilatation or a sigmoid esophagus may not be due to a hypertensive sphincter, and their presence must not necessarily be interpreted as an indication of severity of the disease; there is an inverse correlation between chest pain and symptoms of dysphagia, regurgitation, and weight loss; and finally, achalasia and hiatal hernia may coexist in 6% of the patients.

Adolescent↗
PubMed1989

Effect of aerobic exercise on mouth-to-cecum transit time.

To examine the premise that exercise reduces the gastrointestinal transit time, we evaluated the effect of walking 4.5 km in an hour on mouth-to-cecum transit time. Twenty-three healthy volunteers, 9 men and 14 women, with an age range of 19-28 yr, were studied. After an overnight fast, the subjects ingested 10 g of lactulose in 150 ml of water while breath hydrogen concentrations were analyzed at 15-min intervals. On separate days, in random sequence, subjects either sat in a chair or walked on a treadmill for 60 min. Mean transit time was 55 +/- 8 min when resting and 89 +/- 4 min when exercising (p less than 0.001). In conclusion, light aerobic exercise prolonged the mouth-to-cecum transit time. On the basis of this observation, exercise as a causative factor in runner's diarrhea and its value in the management of chronic constipation may be questioned.

Adult↗
PubMed1988

Effect of anger on colon motor and myoelectric activity in irritable bowel syndrome.

The present investigation was designed to study the effect of anger on colon motor and myoelectric activity in irritable bowel syndrome. Patients with irritable bowel syndrome were compared with normal controls during resting and two anger stressors: criticism of performance on an intelligence test and during a delay of assistance for a diagnostic procedure. At rest patients with irritable bowel syndrome had higher motor and spike potential activity than normal subjects; however, the difference was only significant for spike activity. Anger significantly increased colon motor and spike potential activity in the groups compared with the resting state. Patients with irritable bowel syndrome produced significantly higher motor and spike potential activity when angered. They also reported themselves to be more hostile and appeared angrier than normal controls after the study. However, they did not report themselves to be more anxious or depressed, suggesting that the observed changes in colonic function of both groups were due to anger. Patients with irritable bowel syndrome scored significantly higher than controls on the Minnesota Multiphasic Personality Inventory scales of hypochondriasis, hysteria, and depression, but these personality factors did not significantly influence their anger level before the study. The results are discussed in terms of the role of learning in the colon and the abnormal reinforcement of bowel behavior in patients with irritable bowel syndrome.

Action Potentials↗
PubMed1988

Effect of gastric bubble as a weight reduction device: a controlled, crossover study.

In spite of the widespread use of the Garren-Edwards gastric bubble as an adjuvant device in weight reduction, its efficacy has not been established. Therefore, our purpose was to conduct a randomized, double-blind, crossover study of this device in the management of exogenous obesity. The study group consisted of 23 patients, 21 women and 2 men, ranging in age from 21 to 53 yr. Patients were 25%-111% above their ideal body weight. They were studied for 24 wk, consisting of two separate 12-wk evaluation periods. Patients were randomly assigned either to receive the gastric bubble or to have a sham procedure. After the first 12-wk evaluation period, the gastric bubble and sham were administered in crossover fashion, so that those who had received the gastric bubble initially received the sham later and vice versa. The study coordinator remained blind to the kind of treatment, weighed each patient biweekly, enforced dietary counseling, and provided behavior modification. Those who had passed or were found to have a deflated bubble at the end of the treatment period were excluded from the study. Mean weight reduction in the two evaluation periods did not differ significantly. Patients lost 5.4 +/- 1.7 kg (mean +/- SE) during the gastric bubble period and 5.20 +/- 0.8 kg during the sham period. The order of administration of the gastric bubble and sham did not significantly affect the result. The time-course of mean biweekly values, however, revealed that with the gastric bubble, weight loss was significantly greater only during first (p less than 0.005) and second (p less than 0.025) 2-wk evaluation periods. This difference, however, disappeared after the initial 4 wk of treatment. These observations suggest that although gastric bubble implantation reduced weight significantly more than the sham procedure initially, the mean weight loss during 12 wk of evaluation was not different between the two periods. In our opinion, the gastric bubble is of no value as an adjuvant device in weight reduction.

Adult↗
PubMed1987

Impact of neodecortication on colon motor response to a meal in the rat.

The colon motor response to a meal consisting of 100 mM of sodium oleate was assessed before and after neodecortication in male Sprague-Dawley rats. Recording probes were anchored surgically in the ascending and descending colon. Pressure changes were recorded on a dynograph using a low-compliance perfusion system. A motility index took into account the amplitude, duration, and frequency of contractions. Neodecortication increased the motility index of the distal colon in the fasting state. However, removal of the cerebral cortex did not affect significantly the colon motor response to a meal. Meal stimulation increased the motility index before and after neodecortication. These findings suggest that resting colonic motor activity is increased after neodecortication, probably through the loss of an inhibitory influence of the central nervous system; and the cerebral cortex is not required for the colon response to a meal in the rat.

Animals↗
PubMed1986

The neurovisceral and electrodiagnostic evaluation of patients with thoracic spinal cord injury.

We studied nine patients with complete thoracic spinal cord injury in order to investigate distal electrophysiologic and end organ function. Studies included motor and sensory nerve conduction velocities, spinal and cortical somatosensory evoked responses, bulbocavernosus reflex responses, cystometry and colonic compliance, motor and myoelectrical activity. These studies confirmed an intact peripheral nervous system, as well as normal nerve root, cauda equina, conus medullaris and distal spinal cord function. Cystometry demonstrated decreased bladder capacity and inability to suppress detrusor contractions. Colonic compliance was greatly reduced, compared to control subjects. While basal colonic motor and myoelectrical activity was normal, these spinal cord injury patients failed to demonstrate the postprandial increase in colonic motor and myoelectric activity seen in normal subjects. These tests allow the clinician to define and document the extent of neuronal injury distal to a transverse myelopathy and to evaluate visceral end organ function.

Adult↗
PubMed1986

The renin-angiotensin system in hypothyroidism of short duration.

In six hypothyroid patients (2 male, 4 females, ages 22 through 59 years), plasma renin activity (PRA) and aldosterone (Aldo) were measured when the patients were euthyroid on levothyroxine therapy and one month after the therapy was stopped. Colonic mucosal potential differences were measured during the hypothyroid and euthyroid stages, and catecholamine sensitivity was determined by the blood pressure response to infused norepinephrine. Significant differences were observed in the PRA and aldosterone concentrations which were 4.1 +/- 2.5 ng/ml/h and 9.4 +/- 5.9 ng/dl, respectively in the hypothyroid stage and 6.9 +/- 2.3 ng/ml/h and 15.2 +/- 7.3 ng/dl, respectively when the patients were made euthyroid. The colonic mucosal potential differences (which reflect increased endogenous mineralocorticoid activity), became more electronegative after correction of hypothyroidism (-16.8 +/- 7.5 mV vs -32 +/- 18.2 mV; P less than 0.04) concentrations. Statistically significant decreases in norepinephrine pressor effects were observed in hypothyroid patients when compared to the euthyroid state (7.4 +/- 2.3 vs 10.9 +/- 1.9 micrograms/ng/min; P less than 0.01). It is concluded that patients with hypothyroidism have a hormonal pattern reminiscent of "low renin hypertension", and exhibit decreased sensitivity to catecholamines. Such changes are corrected when the patients become euthyroid on levothyroxine therapy.

Adult↗
PubMed1985

Modified acid reflux test. A benefit and cost analysis.

Although the standard acid reflux test is often used to diagnose gastroesophageal reflux (GER), the cost and benefit of this diagnostic test has never been evaluated. In this study, 184 consecutive referrals with esophageal symptoms were interviewed and had an esophagram, an esophageal manometry, and a modified acid reflux test (MART). The results were analyzed to determine how frequently MART altered the clinical diagnosis and to assess the cost of the new information. Patients with typical symptoms of GER (heartburn or regurgitation) were compared to those with atypical presentation (chest pain or dysphagia). Previously unsuspected GER was demonstrated in 63% of the atypical group, whereas no altered diagnosis was made in the typical group. There was no statistically significant difference between the two groups when mean lower esophageal sphincter pressures and mean pH scores were compared. MART was cost effective only in the atypical group, in which the cost of an altered diagnosis was $633.00.

Adolescent↗
PubMed1985

Colonic absorption of 1,2-dimethyl hydrazine (DMH) in the rat.

1,2-Dimethyl hydrazine (DMH) is absorbed in the colon by passive diffusion in the 0.1-5.0 mM concentration range. Absorption of DMH is enhanced by both conjugated and unconjugated bile acids. The presence of hydroxy-fatty acids in the colon markedly increased DMH absorption while fatty acids of different chain length did not influence absorption.

1,2-Dimethylhydrazine↗
PubMed1985

Effects of thoracic spinal cord transection on colonic motor activity in rats.

The resting colonic motor activity before and consecutively after spinal cord transection was recorded in male Sprague-Dawley rats. Recording probes were anchored surgically in the ascending and descending colon. Pressure changes were recorded on a dynograph using a low compliance perfusion system. A motility index took into account the amplitude, duration and frequency of contractions. Following a baseline recording animals were subjected either to spinal cord transection at T4 level or a sham operation. The recording sessions continued regularly on alternate days for the observation period of 3 weeks. Transection of the thoracic spinal cord markedly reduced the motility index of the distal colon on the first postoperative day. However, the motor activity gradually returned to pre-operative values after 7 days. Sham surgery did not influence the motor activity. These findings suggest that colonic motor activity is influenced by spinal shock and probably by different neural mechanisms mediating proximal and distal activities of the colon in rats.

Animals↗
PubMed1984

Colonic absorption of acetylsalicylic acid in the rat.

Aspirin is absorbed in the colon by passive diffusion to a significant degree in spite of the alkaline pH of the colonic lumen. Aspirin absorption by the colon is enhanced by increasing the hydrogen ion concentration. Butyric acid, by markedly reducing the absorption rate of aspirin, may be partially responsible for the unpredictable absorption of rectally administered aspirin. The addition of glycerol to aspirin preparations does not hinder the absorption of aspirin by the colon.

Animals↗